In the spirit of TMTOWTDI:

$found=0;
open(RAFFLE_DAT,"< tickets.dat") || die "tickets.dat is not found.";
  while(<RAFFLE_DAT>) {
    chop;
    if ($tickennum,$emailaddr)=split(/::/,$line))
      if ($emailaddr eq $email) { $found=1; last; }
    }
 }
close (RAFFLE_DAT) || die "Could not close tickets.dat\n";
if ($found) { &bademail(); }
else { &goodemail; }
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Instead of the chop, you could replace the sixth line with:
if ($emailaddr eq "$email\n") { $found=1; last; }

As an aside, if the ticket numbers are arbitrary, you could always not even use a $tickennum, but just have a list of emails in the file, and the "ticket number" would be their line number:

## Assigns email address to each ticket number
$x=0;
while(<RAFFLE_DAT>) {
  chop;
  $ticket{$x++}=$_; ## or push(@ticket, $_);
}
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